Machine and method for forming a container starting from a reel of material in web form

ABSTRACT

A method for forming a container  7  starting from a web ( 3 ) of heat-bondable material wound on a reel ( 4 ) comprises the following operations: forming a tubular element ( 5 ) of predetermined diameter and height; mounting the tubular element ( 5 ) over a support ( 16 ); closing one end of the tubular element ( 5 ) to form the open container ( 7 ); inserting the container ( 7 ) into a mould ( 12 ) after heating if necessary; forcing the walls of the container ( 7 ) against the inner walls of the mould ( 12 ); opening the mould and withdrawing the container ( 7 ) from the support ( 16 ).

[0001] The present invention falls within the technical sectorconcerning devices and methods for forming containers for liquid,granular and powder materials, for example for drinks, solid orsemi-liquid foods, cleaning products and others.

[0002] In particular, the invention relates to a machine and method forforming a container starting from a reel of thermally bondable materialin web form, such as polyethylene, polypropylene and all plasticmaterials, including those bonded to each other and/or to paper oraluminium.

[0003] Devices are known which, starting from one or more shaped flatsheets of material of the so-called bonded type, are able to form a flatwalled container, for example of parallelepiped or tetrahedron shape,such as those widely used for containing still drinks.

[0004] Devices are also known for forming flat walled containersprovided with opening tabs, stoppers or spouts for pouring out thecontainer contents.

[0005] The main drawback of known devices is the fact that they can formonly flat walled containers generally of parallelepiped shape, and hencevery similar to each other, so preventing characterisation anddifferentiation of the contained product, as instead the industryrequires.

[0006] A further drawback of known devices is the fact that the flatwalls easily deform when internal or external pressures are present, sopreventing packaging of products which generate even small pressures,for example moderately sparkling drinks, and leading to undesirableescape of the product from the opened container if gripped too strongly.

[0007] The main object of the present invention is to propose a machineand method for forming a container starting from a reel of material inweb form which are able to give the container different shapes,including curved walls.

[0008] Another object is to propose a machine and method for providingthe containers with at least a moderate rigidity to resist at leastmoderate internal and external pressures.

[0009] Another object is to propose a machine and method for formingcontainers from continuous webs of synthetic materials bonded toaluminium or paper, or from continuous webs of single-layer syntheticmaterials.

[0010] A further object of the present invention is to propose a machinewhich is of simple construction and maintenance, of high reliability andeconomically advantageous.

[0011] The objects of the invention are attained by a method consistingof folding, and bonding together the edges of, a web unwound from a reelto form a tubular element which is cut into parts of equal length whichare mounted over a preferably cylindrical support.

[0012] The tubular element is then bonded transversely to its axis toform a closed base, or alternatively a separate base is applied to theend of the tubular element, to hence form an open container.

[0013] This latter, still mounted over the respective cylindricalsupport, is inserted into a mould which is closed about the cylindricalsupport, and here subjected to internal pressure after heating.

[0014] The open container hence assumes the shape of the walls of themould to which it adheres, and after opening the mould and aftersuitable cooling it is removed from the tubular support.

[0015] According to the invention, the heating temperature is between30° C. and 60° C., whereas the cooling temperature is between 5° C. and30° C.

[0016] The open edge of the container mounted over the cylindricalsupport can be subjected to an operation for forming a flat flangebefore its insertion into the mould.

[0017] The invention also comprises a machine for forming containersstarting from a web wound on a reel, comprising a station in which theweb is folded into two, bonded along its facing longitudinal edges andcut into tubular elements of equal length.

[0018] An endless conveyor supporting a series of identical cylindricalsupports arranged to receive said tubular elements conveys them to thevarious processing stations.

[0019] The first of these is a bonding station arranged to close one endof the tubular element to form a container.

[0020] The next station is the forming station in which a mould composedof several mutually movable parts is closed about the cylindricalsupport to create a sealed chamber; suitable means for heating acompressed gas and feeding it into the container inflate the containerto force it against the mould walls from which it assumes its shape.

[0021] The mould is then opened and the shaped container withdrawn fromthe respective cylindrical support.

[0022] The merits and the operational and constructional characteristicsof the invention will be more apparent from the ensuing detaileddescription which, with the aid of the accompanying drawings,illustrates a particular preferred embodiment and a variant thereof byway of non-limiting example.

[0023]FIG. 1 is a schematic side view of a first embodiment of themachine of the present invention, from which certain parts have beenremoved in order to better illustrate others.

[0024]FIG. 2 is a view of the machine of FIG. 1 from above, from whichcertain parts have been removed in order to better illustrate others.

[0025]FIGS. 3A, 3B and 3C are respectively a side view, a partial frontview and an enlarged side view of the shaping station.

[0026]FIG. 4 shows a detail of the machine of FIG. 1.

[0027]FIG. 5 is an enlarged perspective view of a container formed bythe machine of FIG. 1.

[0028]FIG. 6 is a schematic side view of a second embodiment of theinvention.

[0029]FIGS. 7 and 8 are respectively an enlarged front view and anenlarged top plan view of elements of the machine of FIG. 6.

[0030]FIG. 9 is a section through the element of FIG. 8 on the planeIX-IX.

[0031]FIG. 10 is an enlarged view from above showing elements of themachine of FIG. 6.

[0032]FIG. 11 is a side view of elements of FIG. 10.

[0033]FIG. 12 is an exploded view of a portion of the container.

[0034] With reference to FIGS. 1 to 4, the reference numeral 1 indicatesthe machine for forming a container of flexible material in web form 3unwound from a reel 4.

[0035] It comprises a pair of endless parallel chains 15 passing aboutintermittently driven sprockets 151, their links carrying a series ofequidistant cylindrical supports 16.

[0036] The supports 16 are individually supported by a parallelepipedbase 30 fixed to the chain links.

[0037] Each support 16 comprises an internally hollow tubular portion 28provided with holes 29 along four generators at 90° apart and isconnected to the underlying base via a groove 330 intended to contain agasket 47 described hereinafter. The interior of the base 30communicates with the outside via conduits 301 visible in FIG. 7, to beconnected to a pressurized gas supply.

[0038] The transverse dimensions and height of the support 16 areslightly less than the corresponding transverse dimensions and height ofthe container 7, the portion 28 of the support 16 being of cylindricalor profiled shape.

[0039] The base 30 consists of a profiled plate. The inner surface ofeach support 16 carries, at its free end portion, an abutment shoulder31 (shown in FIG. 12).

[0040] At one end, namely the left end in FIG. 1, the machine 1comprises a station 2 for forming and cutting a tubular element 5starting from the web wound on the reel 4.

[0041] The means for folding the web into two, bonding it along agenerator to form the tubular element 5, mounting the end of the tubularelement 5 over the cylindrical support 16 lying in a horizontal positionin front of the station 2, and cutting off a determined length of saidtubular element which remains mounted over the support are not describedor illustrated as they are of usual type, easily imaginable anddesignable by the average expert.

[0042] Immediately downstream of the station 2 the machine comprises astation 6 for closing the bottom of the tubular element to create thecontainer 7.

[0043] In the embodiment illustrated in FIGS. 1 and 2, said meanscomprise a pair of heated bonding bars 211 and 212 supportedrespectively by a fixed support 210 and a movable support 21 driven bythe cylinder- piston unit 213 via a lever 214 to be cyclically moved adistance from and close to the fixed support.

[0044] By virtue of the to-and-fro movement, the bonding bars areclamped together onto the outer mouth of the tubular element 5 to closeit and form a container 7.

[0045] Downstream of the station 6 the supports 16 pass below a seriesof profiled metal plates 22 which fold the ends of the bonded edgeinwards towards each other until a presser element consisting of aprofiled punch 23 causes said ends to adhere to the flat closed base ofthe container 7. In particular, said punch compels the container base topartially retract into the container 7 to adhere to its walls.

[0046] Along that portion occupied by the plates 22 the machinecomprises means 17 for forming a flange 18 at the open end of thecontainer 7 facing the base 30.

[0047] Said means comprise an annular abutment 33 axially slidablewithin a seat provided in each base 30 in the region adjacent to thetubular cylindrical portion 28.

[0048] The annular abutments 33 are forced against the open end of thecontainer mounted over the support 16 by reciprocating linear actuators32, shown schematically in FIG. 1, to form a flange 18, shown in FIG. 5and intended to receive a flat closure element.

[0049] To oppose the action of the abutment 33, counteracting means 34are provided, each consisting of clamps disposed transverse to theconveyors 15, which retain the container 7.

[0050] Downstream of the means for flattening the base and forming theflange there is positioned the shaping station 8 in which each container7 undergoes a permanent deformation.

[0051] Said shaping station 8 comprises a mould 12 comprising two facingshells 45 able to be spaced apart to allow entry of the support 16 withthe relative container, and an upper closure member 46.

[0052] The means for moving said shells 45 and said member 46 will notbe described in detail.

[0053] When the conveyor 15 has placed a cylindrical support 16 withinthe shells, these are moved towards each other into mutual contact, andthe member 46 is lowered to form with the base 30 a closed chamber whichsurrounds the support 16.

[0054] Pneumatic means 13 are provided for feeding a pressurized gasinto the support 16.

[0055] By feeding gas at a pressure of between 3 and 30 bar into thesupport 16, the walls of the container 7 are made to adhere to the wallsof the shells 45 and assume their shape. The pneumatic means 13 consistof conduits 301 and 302 provided within the base 30 and connecting asource of compressed gas, such as a motor-driven air compressor, to themould interior via the base 30.

[0056] Said connection via said conduits is made by a pneumatic couplingwhich is connected automatically to them.

[0057] The pneumatic means 13 comprise at least one shut-off valve, suchas a solenoid valve.

[0058] As stated, the supports 16 comprise, in proximity to therespective bases 30, a seat 330 for an annular gasket 47. The seat isconnected to a source of compressed gas via the conduit 302.

[0059] During the formation of the container 7 within the mould 12, thegasket 47 expands by the effect of the compressed gas, for example thepressurized gas fed into the interior of the mould 12, to press themouth portion of the container 7 against the corresponding region of themould 12.

[0060] The shaping station 8 also comprises means 50 (FIG. 3C) forheating the container 7 to a heating temperature of between 30° C. and60° C. The heating means consist, for example, of hot air blowingdevices, or plates provided with electrical resistance elements, orinfrared heaters. The mould 12 can comprise means for cooling thecontainer 7 to a cooling temperature of between 30° C. and 60° C. Thecooling means 7 can comprise an open or closed circuit provided withconduits for circulating a cooling fluid, for example water, whichextend within the walls of the pair of shells 45 and/or the member 46.The cooling means for the container 7 can also comprise a circulationpump and/or at least one solenoid valve, and adjustable temperaturecontrol devices for the fluid.

[0061] When formed and shaped, the containers 7 are removed from therelative supports and transferred by expulsion means, such as compressedair blowers, to exit means 10, consisting for example of conveyor belts.

[0062] In the variant shown in FIGS. 6 to 11, the bonding station 6comprises a positioning means 24, for example of the pick-and-placetype, to position a base 25 against the inner shoulder 31 of the tubularportion 28 of the support 16.

[0063] The base 25, for example circular or polygonal, is provided witha peripheral wall 26 perpendicular to the flat surface of the base.

[0064] Clinching means 27 (FIG. 7) are provided to clinch the end of thewall of the tubular element 5 against the inner surface of theperipheral wall 26, and bonding means 41 for bonding the peripheral wall26 to the wall of the tubular element 5 to form the base of thecontainer 7.

[0065] The clinching means 27 comprise two mutually facing cylindricalidle wheels 35, each provided with an annular lip 36. Each wheel isconnected, via an articulated system (FIGS. 10 and 11), to a unit 40which causes it undergo rotation and translation.

[0066] The unit 40 comprises an idle shaft 401 suspended from themachine frame and connected by a transmission 402 to an electric motor403 for its rotation. The shaft supports a circular plate 404 on whichtwo coplanar angular plates 405 slide, each carrying an articulatedsystem 38.

[0067] This latter comprises a crank, of which the arm 37 c is rotatablyreceived in the angle plate 405 and the arm 37 b supports the pin 37 aof the wheel 35. The arm 37 b is rotatable about its axis relative tothe crank arm, whereas the arm 37 c can translate parallel to itselfrelative to the angle plate 405 (FIG. 11), being connected to thislatter by slidable means 39 d.

[0068] The dimensions of the crank are such that the arm 37 c is alignedwith the diameter of the wheel 35.

[0069] The articulated system 38 also comprises first elastic means 39 aand second elastic means 39 b intended to maintain the wheel 35 urgedagainst the edge of the cylindrical support 16.

[0070] Means are provided for translationally moving the angle plates405 within their plane towards and away from the axis of rotation andfor maintaining them equidistant from this latter.

[0071] To effect clinching, with the unit 40 coaxial to the tubularelement 5, the symmetrical translation of the angle plates 405 causesthe wheels 35 to approach each other until the respective annular lips36 of the wheels 35 rest against the edge of the tubular element 5 atthe free end of the support 16; rotating the unit 40 causes the wheels35 to adhere along the entire path of the end of the support; thesimultaneous movement of the wheels 35 towards the centre due to theprogressive approach of the angle plates 405, in cooperation with therotation, results in progressive clinching of the edge of the containeralong its interior. The tubular element 5 is disengaged from the wheels35 by withdrawing these latter.

[0072] The articulated system 38 enables the wheels 35 to translatetowards the axis of rotation of the unit 40 while varying itsorientation about the axis in order to maintain the lip 36 against theedge of the support element 16 and enable progressive clinching of theedge of the tubular element 5 against the end of the wall 26 of the base25.

[0073] The bonding means 41, only one of which is shown in FIG. 6 forsimplicity, each comprise at least one pair of bonding jaws 42 ofapproximately semi-cylindrical form insertable by insertion actuators 43into those positions of the tubular element 5 which are to be bonded tothe base 25, and divergeable by means of actuators 44.

[0074] The pair of bonding jaws 42 of one bonding means 41 isperpendicular to the pair of bonding jaws of the other bonding means 41to ensure continuity in the bonding of the base 25 to the container 7.

[0075] In operation, the forming and cutting station 2 forms the tubularelement 5, the chains 15 transfer the support means 16 to the bondingstation 6 where the base of the container 7 is formed, then to theshaping station 8 in which the container is given a predetermined shape,and finally to the exit means 10 which convey them for example tostorage devices or to filling and closure machines.

[0076] The method for forming a container 7 starting from a reel ofmaterial in web form 3 comprises:

[0077] forming a tubular element 5 from the web 3 of the reel 4 byfolding the web 3 and bonding together its lateral edges, then cuttingit transversely to obtain a tubular element 5 of predetermined diameterand height;

[0078] mounting the tubular element 5 over a support 16;

[0079] closing one end of the tubular element 5 by linear bonding toform the open container 7;

[0080] forming a flange 18 at the other end of the container 7;

[0081] heating the container 7 to a heating temperature of between 30°C. and 60° C.;

[0082] inserting the container 7 into a mould 12, and closing the mould;

[0083] forcing the walls of the container 7 against the inner walls ofthe mould 12 by feeding gas at a predetermined pressure of between 3 and30 bar into said container 7;

[0084] cooling the container 7 to a cooling temperature of between 30°C. and 6° C.;

[0085] removing the overpressure from the interior of the container 7;

[0086] extracting the container 7 from the mould 12;

[0087] withdrawing the container 7 from the support 16.

[0088] The method also comprises folding the linearly bonded base by theeffect of its interference with fixed guides 22 and pressing the foldedbase towards the interior of the container 7 before shaping its walls inthe mould 12.

[0089] As an alternative to creating the base by linear bonding, themethod comprises applying a base cover 25 close to the mouth of thetubular element 5, then folding the edge of the mouth against the cover25 and finally bonding them together.

[0090] The main advantage of the present invention is the provision of amethod and machine for forming, starting from a reel of web material,containers formed into different shapes comprising curved surfaces.

[0091] A further advantage of the present invention is the provision ofa machine and method for forming containers from sheets of syntheticmaterials bonded to aluminium, paper and deformable crepe paper or fromsingle-layer sheets.

[0092] A further advantage is the provision of a machine which is ofeasy construction and maintenance, of high reliability, and economicallyadvantageous.

1. A method for forming a container 7 starting from a web (3) ofheat-bondable material wound on a reel (4), characterised by comprisingthe following operations: forming a tubular element (5) of predetermineddiameter and height; mounting the tubular element (5) over a support(16) for the tubular element (5); closing one end of the tubular element(5) to form the open container (7); inserting the container (7) into amould (12) after heating if necessary; forcing the walls of thecontainer (7) against the inner walls of the mould (12); opening themould and withdrawing the container (7) from the support (16).
 2. Amethod as claimed in claim 1, characterised by also forming a flange(18) on the mouth of the container prior to its insertion into themould.
 3. A method as claimed in claim 1, characterised in that saidheating temperature is from 30° C. to 60° C.
 4. A method as claimed inclaim 1, characterised in that the pressure is between 3 and 30 bar. 5.A method as claimed in claim 1, characterised in that after opening themould the container is cooled to a temperature between 6° and 30° C. 6.A method as claimed in claim 1, characterised in that the tubularelement is closed by pinch-bonding.
 7. A method as claimed in claim 6,characterised in that after the pinch-bonding the base is folded back byinterference with fixed guides (22) and pressed towards the interior ofthe container (7).
 8. A method as claimed in claim 1, characterised inthat the tubular element is closed by applying a flat cover (25) intothe mouth of the tubular element (5), and then bonding the base.
 9. Amethod as claimed in claim 8, characterised in that before bonding thebase, the mouth edge abutting the cover (25) is clinched onto the cover.10. A method as claimed in claim 1, characterised in that within themould the container undergoes permanent deformation both in the axialdirection and in the longitudinal direction.
 11. A machine for forming acontainer (7) of flexible material starting from web wound on a reel,characterised by comprising an endless conveyor provided withequidistant cylindrical supports (16) and driven intermittently to bringeach of said supports in succession in front of: a station (2) forforming and cutting a tubular element (5) from said web unwound from thereel (4); a station (6) for closing one end of the tubular element (5),to obtain an open container (7); a shaping station (8) provided with amould (12) comprising a plurality of elements (45, 46); pneumatic means(13) for feeding gas under pressure into the container (7) contained inthe mould; means for discharging the shaped container from thecylindrical support after opening the mould.
 12. A machine as claimed inclaim 11, characterised in that the shaping station (8) also comprisesmeans (50) for heating the container (7) to a heating temperaturebetween 30° and 60° C.
 13. A machine as claimed in claim 11,characterised in that the mould (12) also comprises means for coolingthe container (7) to a cooling temperature between 6° and 30° C.
 14. Amachine as claimed in claim 11, characterised in that the conveyor is achain conveyor.
 15. A machine as claimed in claim 11, characterised inthat each support (16) presents a base (39) fixed to the conveyor (15)and a tubular means (28) comprising a plurality of apertures (29)passing through its wall, said support (16) having dimensions less thanthose of the container (7).
 16. A machine as claimed in claim 15,characterised in that the inner surface of each support (16) carries, onits free end portion, an abutment shoulder (31).
 17. A machine asclaimed in claim 14, characterised in that the annular conveyor (15)consists of a reinforced belt.
 18. A machine as claimed in claim 11,characterised by comprising means (17) for forming a flange (18) on oneend of the tubular element (5).
 19. A machine as claimed in claim 18,characterised in that said means comprise annular abutments (33) axiallyslidable within a seat therefor provided in each base (30) in proximityto the relative tubular portion (28) and driven by reciprocating linearactuators (32) to force the annular abutments (33) against the end ofthe relative tubular element (5) or container (7), and stop means (34)therefor.
 20. A machine as claimed in claim 11, characterised in thatthe closure station (6) comprises a pinch bonder (21) which linearlybonds the end portion of the tubular element (5).
 21. A machine asclaimed in claim 20, characterised in that the closure station (6)comprises a plurality of guides (22) for folding the bonded portiontowards the base of the container (7) and punch means (23) which pressthe bonded and folded portion to cause it to adhere to the base of thecontainer (7).
 22. A machine as claimed in claim 11 and claim 16,characterised in that the closure station (6) comprises a means (24) toposition against the shoulder (31) a base (25) provided with a relativeperipheral wall (26); clinching means (27) for clinching the end of thewall of the tubular element (5) against the inner surface of theperipheral wall (26); and bonding means (41) for bonding the peripheralwall (26) to the wall of the tubular element (5) to form the base of thecontainer (7).
 23. A machine as claimed in claim 22, characterised inthat the clinching means (27) comprise at least one idle wheel (35)provided with an annular lip (36) and connected via a relativearticulated system (38) to a rotation and translation inducing means(40).
 24. A machine as claimed in claim 23, characterised in that saidarticulated system (38) comprises a pin (37 a) of the idle wheel (35)connected by a joint (37 b) to a shaft (37 c) orientated perpendicularto the pin (37 a) towards the centre of the wheel (35) and rotatablyassociated with slidable means (37 d) orientated towards the conveyor(15) and having one end fixed to the rotation and translation means(40); said articulated system comprising first elastic means (39 a) andsecond elastic means (39 b) intended to maintain the wheel (35) incontact with the edge of the cylindrical support (16).
 25. A machine asclaimed in claim 22, characterised in that the bonding means (41)comprise at least one pair of bonding jaws (42) of approximatelysemi-cylindrical form insertable by insertion actuators (43) into thoseportions of the tubular element (5) and base (25) which are to be bondedtogether, and divergeable by means of diverger actuators (44) to pressagainst and bond together these latter portions.
 26. A machine asclaimed in claim 25, characterised by comprising two pairs of mutuallyoffset bonding jaws.
 27. A machine as claimed in claim 11, characterisedin that the supports (16) comprise, for an annular gasket (47), a seatconnected to a source of compressed gas, said annular gasket (47) beingintended to expand under the action of the compressed gas.